Such fabric gaps are needed, for example, to produce an insertion edge or special selvage by cutting the weft threads in this fabric gap region. For this purpose, it is known to position a weft thread inserter above the fabric gap, so that cutting the weft thread in the region of said fabric gap and then reinserting the weft thread ends along the gap to form an insertion selvage becomes possible.
The fabric gap is formed in that there are no warp threads in the region of the desired gap in the fabric, so that with the weft thread insertion the gap is crossed only by weft threads which are then present in the gap and cut to form two fabric widths simultaneously.
It is conventionally known to grasp and clamp each beat-up weft thread end with a weft thread end reinsertion device which is independent of the air nozzles which blow the weft thread through an air insertion channel. The reinsertion device reinserts the weft ends back into the shed whereby the weft ends upon beat-up form a fabric edge or selvage. A reed that extends over the entire fabric width is conventionally used in such looms. However, warp threads are not present in the reed or rather in the shed region where the desired fabric gap is to be formed.
It is a disadvantage of the known device that a reed extending over the entire fabric width is relatively costly. If the reed is damaged in any particular area, then it must be replaced as a whole unit.
A further disadvantage of known reeds is seen in that the mechanism forming the weft end reinsertion device must be arranged to be movable and drivable above the fabric web, so that said weft end reinsertion mechanism can be brought outside of the reed reach during the beat-up by the reed.
However, a weft thread end reinserter with a mechanism that is shiftable along the longitudinal axis of the warp threads has the disadvantage that a relatively large structural effort and expenditure are necessary to construct the complete weft thread end reinserter comprising scissors, a clamp and an insertion needle, so that the reinserter is movable longitudinally of the warp threads. Further, valuable time is lost in positioning the complete weft thread end reinserter after the beat-up motion by the reed is completed in order to start the weft insertion through the shed by the conventional air nozzles.